Not a few multifunction peripheral devices (referred to as MFPs below) have a facsimile function for transmitting image data read from a document via a telephone line and an e-mail transmission function for transmitting image data as an attached document utilizing an e-mail delivery system that uses a network circuit such as the Internet or an intranet; an image input device and a printer are integrated with the multifunction peripheral device. Destinations are prestored in a database inside the MFP. The database is often called an address book. A user wishing to transmit image data can easily specify a destination by registering, in a prepared address book, destination information such as facsimile telephone numbers and e-mail addresses and reading and using any of the information from the address book, increasing convenience.
The address book requires management such as addition or modification. To strictly manage the address book, it is desirable to store the address book in a particular device for centralized management. To achieve this, known methods utilize network connections to allow a special management server to manage the address book as described in Japanese Patent Laid-Open Nos. 2001-285520, 2003-233563, and 2003-108479. Japanese Patent Laid-Open No. 2003-134260 describes a technique for informing users of a change in address information.
The techniques based on such centralized management may result in complicated management and time-consuming modifications. Thus, some MFPs allow address books to be easily changed by a large number of users with no particular administrator designated for maintenance of the address books. It is very convenient for users that they can freely register or change entries in the address book with no particular administrator designated. On the other hand, since the individual users can change the contents of the address book, the changed contents may be inappropriate. For example, an operator may mistakenly or intentionally register a facsimile number or mail address different from that of an original destination, in the address book. If a facsimile letter or a mail is transmitted using the incorrect address book entry, it is sent to an incorrect destination that is different from the user's intended one. This results in a double mistake; the information not only fails to be transmitted to the desired destination but is also sent to the destination to which it should not be transmitted. This inconvenience may occur not only in MFPs but also in data transmission devices such as shared computers or facsimile machines in which, for example, a user agent for e-mails allowing general users to maintain the address book is installed.